Protecting Telescope in a Remote Observatory

I'm getting close to having full remote access to my observatory and want to know how others deal with protecting the lens/mirror from dust and dirt when the observatory is closed? I know that the Flip/Flat is available, but are there other methods or do most people just leave the optics uncovered and clean them more often? I'm using a 4" refractor.

I just park my scopes with the apertures uncovered pointing down as far as reasonably possible. The optics stay pretty clean as the dust doesn't settle on the glass. The rest of the scope and mount is a difference story.

Long dew shield and pointed away from the prevailing wind. I also covered the larger gaps with neoprene and the dome base labyrinth with loose air filter material. Still get dust but not as much and in more than a year very little on the optics...

Glad you started this thread. I'm very curious to hear what folks with remote setups are doing on this front. Seems like there's remote gear offered for nearly every application except dust covers. Largest Flip-Flat that's currently offered is 8.25" in diameter. That's too small for my needs. Anyone have a homemade solution to show off?

Some of the larger professional scopes have motorized shutters that close over the primary mirror.

One trick I see every once in a while for amateur refractors is a park position that puts the field lens in a socket or cradle. Absolute encoders and/or limit switches are suggested if you go this way.

Another is a gravity-powered flip-up cover with an extended finger that will close the cover when put into the park position.

Observatory-sealing and air filters are a good idea in dusty locations.

OH, one other point. I have two domes one is 16 feet above ground on a tower, while the other sits at ground level. There is almost no dust in the dome mounted on the tower, and even with the sealing and filtering there is still dust in the dome at ground level. Not to surprising but interesting none the less...

I'm getting close to having full remote access to my observatory and want to know how others deal with protecting the lens/mirror from dust and dirt when the observatory is closed?

I've weatherstripped the openings of my observatory. The road in front of my property is gravel. In the summer I often seen a thick dust cloud envelop the observatory after a vehicle has gone by. Lots of pollen and insects in the area as well. No problem inside the building. I haven't found it necessary to clean the optics or evict any unwanted guests out there in the last three years.

Just for fun I created this concept sketch of an automatic refractor shutter for a robotic observatory. It doesn't require power, electronics or an ASCOM driver.

Put your telescope into a horizontal park position and then move the microphone stand into position and adjust its height and location until the cloth disc perfectly closes over the end of the OTA. The cloth disc shouldn't be stretched tight in the hoop. A small amount of relaxed droop will allow it to conform and seal better to the end of the OTA.

And since the microphone stand is movable and the disc is flexible, if the telescope ever somehow crashes into the shutter system, there shouldn't be much risk of damage to the telescope.

This approach will work best if parking the OTA horizontally instead of pointing at True North.

The way that the mount approaches the horizontal park position will be important. If your particular mount doesn't always approach the park position straight from above, you might need to do an intermediate slew to a location above the park position before commanding the mount into horizontal park.

Hey Chris, that would work! I was experimenting with my mount (EQ-G and EQMod) and found that I can get it to park with the OTA below the horizon, but your design is a good idea. I'll let you know if I put it together.

Thanks for your efforts.

Larry(But why did I put up an Observatory in Minnesota? This weather has been hideous!)

Hey Chris, that would work! I was experimenting with my mount (EQ-G and EQMod) and found that I can get it to park with the OTA below the horizon, but your design is a good idea. I'll let you know if I put it together.

Thanks for your efforts.

Larry
(But why did I put up an Observatory in Minnesota? This weather has been hideous!)